A generalised additive model to characterise dairy cows’ responses to heat stress

Heat stress is one of the most critical issues jeopardising animal welfare and productivity during the warm season in dairy cattle farms. The global trend of increase in average and peak temperatures is making the problem more and more serious. Many devices have been introduced in livestock farms to monitor and control temperature-humidity index, as well as animal behaviour and production parameters. The consequent availability of collected databases has increasingly enhanced the research aimed to understand the consequences of heat stress in cattle, in relation to genetic, reproductive, productive and behavioural features. Moreover, these investigations laid the foundations for the development, calibration, validation and test of numerical models quantifying the individual responses to heat stress conditions. In this work, a generalised additive model with mixed effects has been developed to analyse the relationship between milk production, animal behaviour and environmental parameters based on data surveyed in 2016 in an Italian dairy farm. Each cow has been characterised in terms of her response to heat conditions, and the results led to define three classes of susceptibility to heat stress within the herd. These attributes have then been related to the various phenotypic parameters collected by the precision livestock farming devices used in the farm. The study provides a model to understand the effects of heat stress conditions on individual animals in relation to the main parameters describing their rearing conditions; moreover, the results contribute to improve the herd management by lending indications to define targeted treatments according to the cow’s characteristics.     

Polyomavirus inactivation – A review

Polyomavirus inactivation has been studied since the 1950s when it became apparent that certain polio vaccines were contaminated with SV40. Relatively high temperatures (≥70 °C) are required to effect thermal inactivation of the polyomaviruses. The chemical inactivants that are effective (β-propiolactone, ethanol, sodium hydroxide, and formaldehyde) are those that have displayed efficacy for other small, non-enveloped viruses, such as the circoviruses. Low pH inactivation can be effective, especially at pH at or below 3 and at higher temperatures. Polyomaviruses are more resistant to UV-C irradiation than are other small non-enveloped viruses such as the parvoviruses and caliciviruses. The efficacy of photodynamic inactivation of polyomaviruses is very much dye-dependent, with toluidine blue, acridine orange, and methylene blue dyes being effective photosensitizers. Ionizing radiation can be effective, depending on the conditions employed and the inactivation matrix. Inactivation of the oncogenic properties of the polyomaviruses may require higher doses of inactivant than those required to inactivate infectivity. While the polyomaviruses are considered to be highly resistant to inactivation, the degree of resistance is dependent upon the specific approach under consideration. For certain approaches, such as UV-C and gamma-irradiation, the polyomaviruses appear to be more resistant than other small non-enveloped viruses.     

Physiological and ecological responses to drought and heat stresses in Osmanthus fragrans ‘Boyejingui’

为了探讨植物对干旱、高温及协同胁迫的响应, 该研究以木犀(Osmanthus fragrans) ‘波叶金桂’为材料, 采用盆栽质量控水法模拟干旱胁迫(对照、轻度、中度和重度)和高温胁迫, 利用动态顶空气体循环吸附法和热脱附-气相色谱-质谱(TDS-GC-MS)联用技术对其挥发性有机化合物(VOCs)进行测定; 同时测定其非结构性碳(NSC)含量及次生代谢酶活性。结果表明: 干旱胁迫对‘波叶金桂’叶片NSC组分含量影响不显著; 可溶性糖和淀粉含量在高温胁迫下显著降低, 在协同胁迫后持续性下降, 重度协同胁迫下, 葡萄糖、果糖、蔗糖和淀粉分别比对照降低47.7%、46.4%、34.4%和38.2%。干旱胁迫和协同胁迫下3-羟基-3-甲基戊二酸单酰辅酶A还原酶(HMGR)、1-脱氧木酮糖-5-磷酸还原酶(DXR)活性表现出先上升后下降, 而脂氧合酶(LOX)活性表现出持续性上升趋势; 高温胁迫后, HMGR、DXR和LOX活性显著高于对照。干旱胁迫下萜烯类VOCs释放量表现出先上升后下降趋势, 中度干旱胁迫和高温胁迫下分别比对照高37.9%和32.3%; 协同胁迫下萜烯类释放量逐渐降低, 干旱、高温和协同胁迫诱导醛类释放量明显增加。上述结果表明: 干旱胁迫条件下, ‘波叶金桂’通过NSC进行自我渗透调节, 同时合成大量萜烯类化合物来提高抗旱性; ‘波叶金桂’调控萜烯类化合物合成以及绿叶挥发物(GLVs)的释放抵御高温胁迫; 协同胁迫下萜烯类化合物的合成途径受阻, ‘波叶金桂’提高GLVs合成与释放量抵御协同胁迫; 中度和重度协同胁迫导致‘波叶金桂’细胞膜严重受损, 自我调节能力降低。     

A slide down a slippery slope – alpine ecosystem responses to nitrogen deposition

Background: Nitrogen (N) deposition in the Front Range of the southern Rocky Mountains has been increasing for several decades, and has exceeded the critical load for several ecological metrics.

Aims: Our objective was to predict potential future ecological changes in alpine zones in response to anthropogenic N deposition based on a review of research from Niwot Ridge, Colorado.

Results: Empirical observations and experimental studies indicate that plant, algal and soil microbe species compositions are changing in response to N deposition, with nitrophilic species increasing in abundance. Biotic sequestration of N deposition is insufficient to compensate for greater nitrate production, leading to the potential for acidification and base cation loss.

Conclusions: Changes in biotic composition in both terrestrial and aquatic ecosystems have important impacts on ecosystem functioning, including a lower capacity to take up and neutralise the acidifying effect of anthropogenic N, increasing phosphorus limitation of production in terrestrial and aquatic systems, and shifts in rates of N and carbon cycling. Continued elevated N deposition rates coupled with ongoing climate change, including warmer summer temperatures and lower snow cover of shorter duration, will influence the ecological thresholds for biotic and functional changes. We suggest that these thresholds will occur at lower inputs of N deposition under future climate change, meriting reconsideration of current N critical loads to protect sensitive alpine ecosystems.     

Disgust sensitivity relates to affective responses to – but not ability to detect – olfactory cues to pathogens

Hundreds of studies have assessed variation in the degree to which people experience disgust toward substances associated with pathogens, but little is known about the mechanistic sources of this variation. The current investigation uses olfactory perception and threshold methods to test whether it is apparent at the cue-detection level, at the cue-interpretation level, or both. It further tests whether relations between disgust sensitivity and olfactory perception are specific to odors associated with pathogens. Two studies (N's = 119 and 160) of individuals sampled from a Dutch university each revealed that pathogen disgust sensitivity relates to valence perceptions of odors found in pathogen sources, but not to valence perceptions of odors not associated with pathogens, nor to intensity perceptions of odors of either type. Study 2, which also assessed olfactory thresholds via a three-alternative forced-choice staircase method, did not reveal a relation between pathogen disgust sensitivity and the ability to detect an odor associated with pathogens, nor an odor not associated with pathogens. In total, results are consistent with the idea that pathogen disgust sensitivity relates to how olfactory pathogen cues are interpreted after detection, but not necessarily to the ability to detect such cues.     

Canine transmissible venereal tumor – From general to molecular characteristics: A review

Cancer is a group of complex diseases resulting from the accumulation of genetic and epigenetic changes affecting control and activity of several genes, especially those involved in cell differentiation and growth processes, leading to an abnormal proliferation. When the disease reaches an advanced stage, cancer can lead to metastasis in other organs. Interestingly, recent studies have shown that some types of cancer spread not only through the body, but also can be transmitted among individuals. Therefore, these cancers are known as transmissible tumors. Among the three types of transmissible tumors that occur in nature, the canine transmissible venereal tumor (CTVT) is known as the oldest cancer in the world, since it was originated from a single individual 11 000 years ago. The disease has a worldwide distribution, and its occurrence has been documented since 1810. The CTVT presents three types of cytomorphological classification: lymphocytoid type, mixed type, and plasmacytoid type, the latter being chemoresistant due to overexpression of the ABCB1 gene, and consequently increase of the P-glycoprotein. More knowledge about the epidemiology and evolution of CTVT may help to elucidate the pathway and form of the global spread of the disease.     

Beneficial endophytic microorganisms of Brassica – A review

Brassica species display enormous diversity and subsequently provide the widest assortment of products used by man from a single plant genus. Many species are important for agriculture, horticulture, in bioremediation, as medicines, soil conditioners, composting crops, and in the production of edible and industrial oils such as liquid fuels and lubricants. Many wild Brassica relatives possess a number of useful agronomic traits, including beneficial microbial endophytes that could be incorporated into breeding programs. Endophytes of Brassica, and/or their metabolites, have been demonstrated to improve and promote plant growth; increase yield; reduce disease symptoms caused by plant pathogens; reduce herbivory from insect pests; remove contaminants from soil; improve plant performance under extreme conditions of temperature and water availability; solubilise phosphate and contribute assimilable nitrogen to their hosts. Brassica napus (oilseed rape) and Brassica oleracea var. botrytis (broccoli and cauliflower) are the most economically important species of Brassica worldwide. These commercial crops are attacked by a wide range of pathogens and insect pests that are responsible for millions of dollars in lost revenue, with current control options offering little mitigation. No alternative control products are available for the Brassica industry, although it has been well documented in the literature that the use of endophytic microorganisms can offer beneficial traits to their host plants, including pest and disease resistance. The aim of this review is to describe the literature concerning beneficial microbial endophytes and their prospects to enhance or provide additional traits to their Brassica host species.     

Mycorrhizal responses to biochar in soil – concepts and mechanisms

Experiments suggest that biomass-derived black carbon (biochar) affects microbial populations and soil biogeochemistry. Both biochar and mycorrhizal associations, ubiquitous symbioses in terrestrial ecosystems, are potentially important in various ecosystem services provided by soils, contributing to sustainable plant production, ecosystem restoration, and soil carbon sequestration and hence mitigation of global climate change. As both biochar and mycorrhizal associations are subject to management, understanding and exploiting interactions between them could be advantageous. Here we focus on biochar effects on mycorrhizal associations. After reviewing the experimental evidence for such effects, we critically examine hypotheses pertaining to four mechanisms by which biochar could influence mycorrhizal abundance and/or functioning. These mechanisms are (in decreasing order of currently available evidence supporting them): (a) alteration of soil physico-chemical properties; (b) indirect effects on mycorrhizae through effects on other soil microbes; (c) plant–fungus signaling interference and detoxification of allelochemicals on biochar; and (d) provision of refugia from fungal grazers. We provide a roadmap for research aimed at testing these mechanistic hypotheses.     

Shift work and diabetes – A systematic review

Diabetes mellitus is a chronic disease, which has an increasing trend all over the world. Type 2 diabetes constitutes 90% of all diabetes. It is associated with weight gain and insulin resistance. Research during recent years has suggested that shift work could be a risk factor of type 2 diabetes. Since shift work is becoming more common, it could contribute to the increasing trend of diabetes. In this systematic review, we have studied the potential association between shift work and type 2 diabetes. We have also reviewed studies on control of diabetes in relation to shift work.     

Possible anti-obesity therapeutics from nature – A review

Obesity is associated with many diseases, particularly diabetes, hypertension, osteoarthritis, and heart disease. The obesity incidence has increased at an alarming rate in recent years, becoming a worldwide health problem, with incalculable social costs. Two different obesity-treatment drugs are currently on the market: orlistat, which reduces intestinal fat absorption via inhibiting pancreatic lipase; and sibutramine, an anorectic or appetite suppressant. Both drugs have hazardous side-effects, including increased blood pressure, dry mouth, constipation, headache, and insomnia. For this reason, a wide variety of natural materials have been explored for their obesity treatment potential. These are mainly complex products having several components with different chemical and pharmacological features. This review aimed to survey the literature covering natural products with anti-obesity activity and to review the scientific data, including experimental methodologies, active components, and mechanisms of action against obesity.     

Alanine dehydrogenase and its applications – A review

Alanine dehydrogenase (AlaDH) (E.C.1.4.1.1) is a microbial enzyme that catalyzes a reversible conversion of L-alanine to pyruvate. Inter-conversion of alanine and pyruvate by AlaDH is central to metabolism in microorganisms. Its oxidative deamination reaction produces pyruvate which plays a pivotal role in the generation of energy through the tricarboxylic acid cycle for sporulation in the microorganisms. Its reductive amination reaction provides a route for the incorporation of ammonia and produces L-alanine which is required for synthesis of the peptidoglycan layer, proteins, and other amino acids. Also, AlaDH helps in redox balancing as its deamination/amination reaction is linked to the reduction/oxidation of NAD⁺/NADH in microorganisms. AlaDH from a few microorganisms can also reduce glyoxylate into glycine (aminoacetate) in a nonreversible reaction. Both its oxidative and reductive reactions exhibit remarkable applications in the pharmaceutical, environmental, and food industries. The literature addressing the characteristics and applications of AlaDH from a wide range of microorganisms is summarized in the current review.     

The potential of earthworms to restore ecosystem services after opencast mining – A review

Opencast coal mining has several environmental impacts, which require land rehabilitation when mining operations are finished. For that reason, restoration after such extractive industries’ work is common and has been well studied. However, many ecological restoration schemes do not examine to what extent complete and functioning ecosystems have been restored above and below ground. While the aim should be to restore functioning ecosystems, most restoration plans focus only on vegetation and above ground macro-fauna.Among the potential species that are likely to be important early in mine land restoration, earthworms are particularly good candidates. They provide several ecosystem services that are likely to accelerate soil restoration, improve primary production and facilitate the restoration of a functional ecosystem in mining areas. These services include the following: increase in topsoil fertility, food for a wide range of predators and recycling of waste organic materials on rehabilitated areas.Here, we outline some of the challenges specifically facing opencast mining restoration and describe how the ecosystem services provided by earthworms may address some of these challenges.     

Questions and answers to edibility problem of the Canavalia ensiformis seeds – A review

The seed of Canavalia ensiformis (jackbean), a highly productive large-seeded tropical legume, contains about 300 g crude protein and 600 g carbohydrates kg⁻¹ dry matter. It, however, contains toxic and antinutritional factors which limit its use as human food or animal feed. The trypsin inhibitors in the seed have, however, been reported to be easily inactivated by moist heat. The toxic alkaline non-protein amino acid, canavanine (present at about 50 g kg⁻¹ seed dry matter), a naturally occuring analog of l-arginine, has also been reported to induce reduced feed intake in non-ruminants but at the equivalent of about 300 g kg⁻¹ dietary level of the raw seed, or in the condition of dietary arginine deficiency. The concentrations of the specialized secondary plant biomolecules – cyanogenic glycosides, saponins, alkaloids and terpenoids – have also been shown to drop below detectable levels following 1 h of cooking. Urease and canatoxin which were isolated from the seed are highly toxic if injected into experimental animals but exert no toxic effects if orally administered, and thus cannot be classified as antinutritional factors. Concanavalin A (Con A), the most studied of plant lectins, appears to be the most important toxic and antinutritional factor in the seed, being highly resistant to heat treatments and to proteolytic digestion in the gut. It requires 3 h of cooking at 96°C or 45 min of pressure cooking; 48 h of soaking the seed in water prior to cooking for 2 h; 72 h of soaking in water prior to ordinary cooking for 1 h; pressure-cooking for 15 min, to completely eliminate it from the seed. Complete inactivation of Con A in the seed can, however, be easily achieved if the seed is broken into pieces and cooked for 1 h or pressure-cooked for 15 min.     

Does increased heat resistance result in higher susceptibility to predation? A test using Drosophila melanogaster selection and hardening

Heat resistance of ectotherms can be increased both by plasticity and evolution, but these effects may have trade‐offs resulting from biotic interactions. Here, we test for predation costs in Drosophila melanogaster populations with altered heat resistance produced by adult hardening and directional selection for increased heat resistance. In addition, we also tested for genetic trade‐offs by testing heat resistance in lines that have evolved under increased predation risk. We show that while 35/37 °C hardening increases heat resistance as expected, it does not increase predation risk from jumping spiders or mantids; in fact, there was an indication that survival may have increased under predation following a triple 37 °C compared to a single 35 °C hardening treatment. Flies that survived a 39 °C selection cycle showed lower survival under predation, suggesting a predation cost of exposure to a more severe heat stress. There was, however, no correlated response to selection because survival did not differ between control and selected lines after selection was relaxed for one or two generations. In addition, lines selected for increased predation risk did not differ in heat resistance. Our findings suggest independent evolutionary responses to predation and heat as measured in laboratory assays, and no costs of heat hardening on susceptibility to predation.     

Effects of shear stress on microalgae – A review

Cultivation of microalgae requires consideration of shear stress, which is generated by operations such as mixing, circulation, aeration and pumping that are designed to facilitate mass and heat transfer as well as light distribution in cultures. Excessive shear stress can cause increased cell mortality, decreased growth rate and cell viability, or even cell lysis. This review examines the sources of shear stress in different cultivation systems, shear stress tolerance of different microalgal species and the physiological factors and environmental conditions that may affect shear sensitivity, and potential approaches to mitigate the detrimental effects of shear stress. In general, green algae have the greatest tolerance to shear stress, followed by cyanobacteria, haptophytes, red algae, and diatoms, with dinoflagellates comprising the most shear-sensitive species. The shear-sensitivity of microalgae is determined primarily by cell wall strength, cell morphology and the presence of flagella. Turbulence, eddy size, and viscosity are the most prominent parameters affecting shear stress to microalgal cells during cultivation.     

Tropical biodiversity loss and people – A brief review

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Massive anthropogenic land use changes are taking place in the tropics. These changes have not only jeopardized native biodiversity but also people. Environmental apathy, corruption, poor natural resource governance, poverty and lack of conservation funding remain formidable challenges for conservation biologists. Any meaningful success in tropical conservation will, hence, need active collaboration by the civil society, biologists, social scientists, lawyers, funding agencies, national and multinational corporations, governments and non-governmental organizations. Concerted research efforts are urgently needed to understand the imperiled tropical biodiversity.     

Hand pollination of global crops – A systematic review

Global pollinator declines and land-use change can lead to pollination limitation with implications for agricultural productivity. Hand pollination is used in agricultural production as a technique to manually pollinate crops. But the prevalence of hand pollination, as well as benefits and costs, remain unknown. We systematically reviewed the literature for examples, methods, drivers, and economic motivations of hand pollination. Furthermore, we discuss the risks, constraints, and opportunities of hand pollination. We found evidence for 20 hand-pollinated crops, including minor but also economically important crops (e.g. apple, oil palm, cacao). The lack of pollinators was the most important reason for the application of hand pollination (50% of crops), while insufficient proportion or proximity of pollinizers (8% of crops) and skewed sex ratio or dichogamy (8% of crops) were second most important. The main economic motivations for practicing or recommending hand pollination were to increase fruit set, and/or fruit quality (78% of crops). Hand pollination is practiced in large- and small-scale farming, home gardens, and greenhouses. Opportunities of hand pollination are the control of pollen origin and quantity, pollination timing and frequency as well as independence from environmental fluctuations. Farmers can increase yields, improve fruit quality, avoid fruit abortion, increase employment, and secure subsistence food. The main constraints of hand pollination are high labor inputs, high material costs, and required skills. Major risks of hand pollination include management ignoring pollinator conservation, high food prices, over-pollination, labor accidents, and unfair labor. We conclude that in the face of global change, hand pollination allows improved control of pollination and is likely to increase in importance. The benefits of hand pollination need to outweigh the costs and fair labor is essential. Altogether, hand pollination can be a valuable tool for crop systems where pollinators are absent or are not reliable for sustaining high-quality crop production.     

Microbial degradation and deterioration of polyethylene – A review

The ability of microorganisms to use polyethylene as a carbon source has only been recently established. This result has significance both from an environmental point of view, due to the accumulation of millions of tons of waste plastics every year, but also regarding the conservation of integrity for infrastructures incorporating this plastic. A number of microorganisms with the ability to grow on polyethylene have been isolated. The effects of these microorganisms on the physiochemical properties of this polymer have been described; these include changes in crystallinity, molecular weight, topography of samples and the functional groups found on the surface. Although the bio-degradation and bio-deterioration of polyethylene has been demonstrated by several researchers, the enzymes involved and mechanisms associated with these phenomena are still unclear. Nevertheless, it is recognized that both enzymatic and abiotic factors (such UV light) can mediate the initial oxidation of polyethylene chains, and given the chemical similarity between polyethylene and olefins it has been suggested that the metabolic pathways for degradation of hydrocarbons can be used once the size of polyethylene molecules decrease to an acceptable range for enzyme action (typically from 10 to 50 carbons). The long-range structure and morphology of polyethylene have shown important roles, with amorphous regions being more prone to microbial attack than crystalline ones. This review focuses on the recent hypotheses and experimental findings regarding the biodegradation of polyethylene.